Temporal "Cloaks of Invisibility" for Events

Over a year ago

by Dominic Basulto

Ever since scientists in Germany announced last year the ability to create a small-scale cloak of invisibility for a 3D object the size of a human hair, there has been growing excitement about the ability to extend this “cloak of invisibility” to larger objects. Now, researchers at Cornell led by Moti Fridman have gone one step further – they have shown that it is theoretically possible to create temporal “cloaks of invisibility” to hide events. In other words, for incredibly brief periods of time – no more than 120 microseconds – it is possible to create a “hole in time” where events can not be observed.

This is the proverbial “time warp” that works by bending space-time in such a way that renders an event invisible. This is exciting work, occurring at the fringes of everything we thought was possible through quantum physics. Yes, it’s time to re-read your Einstein, Hawking and Kaku. Unlike traditional “cloaks of invisibility,” which work by using meta-materials to hide an object from visible light, the “cloaks of invisibility” for events work not by changing the shape of a light wave hitting an object, but by shifting the time of a light wave:

“Current work in developing invisibility cloaks tries to hide an object spatially. Like a magician using a complex set of mirrors to hide his tricks, a invisibility cloak uses materials that change the shape of light so that it moves around an object, hiding it from view. What the researchers at Cornell are doing is similar: they’re taking advantage of the fact that, according to current theories in physics, time and space are equivalent – and instead of focusing on changing the shape of light, they’re focused on changing its time... The researchers began their experiment by creating two time lenses. Unlike a normal lens, which compresses or changes the actual shape of a light wave through diffraction, a time lens magnifies or compresses the time of a light wave through dispersion.”

Thus far, the researchers have only been able to “cloak” events for 110 nanoseconds at a time. We’re not talking about bending space-time for long periods of time, but that could change as the researchers perfect their methodology. Think of the possibilities if giant “cloaks of invisibility” really were possible to hide events in time, and we were able to create mini “holes” in time. Would it be similar to special effects in Hollywood movies, where the action stops for everyone, and one character is free to move around doing as he or she pleases, before the action resumes? Or think bigger – what if these giant “cloaks of invisibility” were used by the U.S. military as part of surprise raids on terrorist outposts?

The future just happened -- but you missed it. What’s fascinating is that theoretical physics – perhaps the one field remaining in modern science that remains almost completely impenetrable to the Average Joe and Josephine – is now combining with Hollywood's built-in mass audience for Harry Potter-style Cloaks of Invisibility to spur radical new breakthroughs at the quantum level. Let’s do the time warp again.